Codex Mini vs Llama 3.1 405B

Compare OpenAI and Meta (via Together AI) AI models

OpenAI

Codex Mini

Meta (via Together AI)

Llama 3.1 405B

Try OpenAI →Try Meta (via Together AI) →

Cost Comparison (1000 input + 500 output tokens, 100 requests/day)

Codex Mini

Per Request:$0.004500

Daily:$0.45

Monthly:$13.50

Yearly:$164.25

Llama 3.1 405B

Per Request:$0.005250

Daily:$0.525

Monthly:$15.75

Yearly:$191.625

Cost Differences

+$0.000750

Per Request

+$0.075

Daily

+$2.25

Monthly

+$27.375

Yearly

Llama 3.1 405B costs more than Codex Mini

Feature Comparison

Feature	Codex Mini	Llama 3.1 405B
Provider	OpenAI	Meta (via Together AI)
Input Price	$1.50/1M tokens	$3.50/1M tokens
Output Price	$6.00/1M tokens	$3.50/1M tokens
Context Window	200,000 tokens	128,000 tokens
Max Output	32,768 tokens	32,768 tokens
Category	efficient	flagship
Capabilities	textcodereasoning	textcodereasoning
Release Date	2/2/2026	7/23/2024

Codex Mini vs Llama 3.1 405B: Which Should You Choose?

Choosing between Codex Mini and Llama 3.1 405B depends on your priorities: cost efficiency, context length, or raw capability. Llama 3.1 405B is the more affordable option at $3.50/1M input tokens. Meanwhile, Codex Mini offers a significantly larger context window at 200,000 tokens vs 128,000 for Llama 3.1 405B.

These models come from different providers — OpenAI and Meta (via Together AI) — which means different API ecosystems, SDKs, rate limits, and terms of service. If you're already integrated with OpenAI, switching to Meta (via Together AI)involves migration effort beyond just pricing. Factor in your existing infrastructure when deciding.

These models target different tiers: Codex Mini is a efficient model while Llama 3.1 405B is flagship. This means they're optimized for different workloads. Llama 3.1 405B targets more demanding workloads, while Codex Mini provides a cost-effective option for everyday tasks.

Output costs matter too. Codex Mini charges $6.00/1M output tokens vs $3.50 for Llama 3.1 405B. For generation-heavy workloads (content creation, code generation, summarization), output pricing often dominates your bill. Llama 3.1 405B has the edge here at $3.50/1M output tokens.

Best Use Cases

Choose Codex Mini when:

• Budget is a primary concern
• You need a larger context window (200,000 tokens)
• You're already using OpenAI's API ecosystem
• You're running high-volume, latency-sensitive workloads

Choose Llama 3.1 405B when:

• You're already using Meta (via Together AI)'s API ecosystem

Try Different Scenarios

Use the calculator below to see how costs change with different usage patterns

Codex Mini (OpenAI)

Cost Calculator

Provider

Model

Input Tokens

Output Tokens

Requests/Day

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Llama 3.1 405B (Meta (via Together AI))

Cost Calculator

Provider

Model

Input Tokens

Output Tokens

Requests/Day

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Start using Codex Mini today

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Frequently Asked Questions

Which is cheaper, Codex Mini or Llama 3.1 405B?▼

Llama 3.1 405B is cheaper for input tokens at $3.50 per million tokens vs $1.50 for Codex Mini.

What is the context window difference between Codex Mini and Llama 3.1 405B?▼

Codex Mini supports 200,000 tokens while Llama 3.1 405B supports 128,000 tokens — a difference of 72,000 tokens in favor of Codex Mini.

Which model is better for AI Agent / Agentic Workflows?▼

Both models support text, code, reasoning. For ai agent / agentic workflows, Llama 3.1 405B is the lower-cost option, while Codex Mini offers a larger context window (200,000 vs 128,000 tokens). Choose Llama 3.1 405B for budget sensitivity or Codex Mini for longer context tasks.

Which model has better overall pricing for heavy usage?▼

At 100 requests/day with 1,000 input and 500 output tokens each, Codex Mini costs about $13.50/month and Llama 3.1 405B costs about $15.75/month. Overall, Llama 3.1 405B has lower combined input + output rates ($3.50 in, $3.50 out) vs Codex Mini.